CAFFEINE EFFECTS

How Caffeine Effects Your Body

Learn what influence caffeine has on your body

How Caffeine Effects Your BodyLearn what influence caffeine has on your body

Chris Shipman

Do you belong in rehab? Maybe not the 12-step kind, but there's a good chance you're among the millions who can't crawl out of bed without the promise of caffeine, your drug of choice. We love to love our java, the ultimate energy shortcut -- it's cheap, guilt free, and practically everywhere. In fact, research increasingly supports a caffeinated life. One recent study at Johns Hopkins Bloomberg School of Public Health found that subjects who drank 4 or more cups of coffee a day lowered their risk of developing type 2 diabetes by a third. And every athlete knows that a jolt of caffeine an hour before exercise can improve endurance. Not to mention that it's a surprisingly robust source of antioxidants. We could go on

There's a dark side to your daily Venti, though. Caffeine can cause high blood pressure, and it may contribute to miscarriage and osteoporosis. Heart palpitations, headaches, irritability, and/or aggression are all signs of an affair gone wrong. "We've seen women who thought they were having panic attacks but were just drinking too much coffee," says Mark Gold, M.D., professor of psychiatry and neuroscience at the University of Florida College of Medicine.

So how should you harness caffeine for energy without twitching for a hit? First, pay attention to how much you're really drinking: Not only is caffeine found in cola (31mg), RedBull (67 mg), and dark chocolate candy bars (30 mg), it's also in a lot of "decaf" drinks. When Bruce Goldberger, Ph.D., a professor at the University of Florida, bought 22 decaffeinated beverages, he was shocked to find that caffeine amounts ranged from none to nearly 14 milligrams per 16-ounce cup. (That's enough to zap lightweights. In a separate study, more than half the participants felt caffeinated after just 18 milligrams.) And fully caffeinated drinks are more turbocharged than ever. In 2003, Goldberger found between 259 and 564 milligrams of caffeine in 16 ounces of Starbucks coffee. "A NoDoz contains 200 milligrams, and some cups of coffee have nearly three times that," he notes.

If you want to scale back, start by substituting a cup of green tea for every cup of coffee. You'll still consume 30 milligrams of caffeine, but tea has theanine, an amino acid with calming effects. Just cut yourself off after 3 p.m. or risk a sleepless night.